Chapter 5: FN100 Diagnostics and TroubleshootingPage 5-6Fast Network 100 User Guide5.4.2 Power Supply FuseThe power supply contains a 3.15 ampere 250 V slow-blow fuse locatedimmediately above the three-prong power input connector on the back ofthe FN100. If you think this fuse may have blown, inspect it for visibledamage and replace it if necessary.In most cases, any damage to the fuse will be readily apparent (e.g.,shattered fuse, blackened glass, broken fuse element). If you do not seeany damage, but still suspect a fuse problem, try replacing the fuse.To replace the fuse:1. Power off the FN100 and disconnect the power cord.2. Pull the small plastic fuse drawer next to the ON/OFF switch outward.3. Remove and replace the fuse.4. Push the fuse drawer back into the housing until it snaps into place.5. Reconnect the power cord and power up the FN100.5.4.3 Connectivity Problems• Check for LED abnormalities.• Check port status using LCM.• Check for loose port connections.• Check to see if the number of carrier losses is increasing using LCM.This indicates that the connection is suspect.• Check to see if the number of total collisions has dramaticallyincreased using LCM.• If problems persist, contact Cabletron Systems Technical Support.!CAUTIONFor protection against fire hazard, replace only with 250Vslow-blow 3.15 ampere fuses.
